DFT-GGA method of Perdew-Burke-Ernzerhof (PBE) is used with aug-cc-PVTZ, 6-311++G**, and Def2-TZVP large basis sets to study the hydrogen bond interactions between oxygen lone pair as a donor electron with hydrogen atom connected to the aniline’s nitrogen as an electron acceptor (H2O···HNH-Ph), and nitrogen lone pair with hydrogen of water molecule (Ph-H2N···HOH...

Herein, we report the structural, electronic, and charge transfer properties of N-[5′-methyl-3′-isoxasolyl]-N-[(E)-1-(-2-thiophene)] methylidene] amine (L) its Fe2+, Co2+, Ni2+, Cu2+, Zn2+ complexes (dubbed A, B, C, D, E, respectively) using density functional theory (DFT). All molecules investigated were optimized at BP86/def2-TZVP/RI level theory. Single point energy calculations carried out ...

density-functional-based and ab initio calculations were implemented at different computational levels to estimate the binding energy of zn2+ ion adsorbed on the available sites of a silicate mel-type adsorbent. b3lyp and mp2 were used in combination with the 6-31g*, 6-31+g*, lanl2dz, 6-311+g*, and def2-tzvp basis sets. the zinc cation was found to preferentially occupy the 6mr sites followed b...

Hirshfeld atom refinement (HAR) is a novel X-ray structure refinement technique that employs aspherical atomic scattering factors obtained from stockholder partitioning of a theoretically determined tailor-made static electron density. HAR overcomes many of the known limitations of independent atom modelling (IAM), such as too short element-hydrogen distances, r(X-H), or too large atomic displa...

The validity of the maximum hardness principle (MHP) is tested in the cases of 50 chemical reactions, most of which are organic in nature and exhibit anomeric effect. To explore the effect of the level of theory on the validity of MHP in an exothermic reaction, B3LYP/6-311++G(2df,3pd) and LC-BLYP/6-311++G(2df,3pd) (def2-QZVP for iodine and mercury) levels are employed. Different approximations ...

Department of Chemistry, Brown University E-mail: [email protected] † Electronic supplementary information ( Nb2Au6 at (a) 616.86 nm, (b) 610.55 nm relative energies of low-lying isomers of PBE0 (in square brackets), CCSD (in bra levels; the four lowest-lying isomers of N valence canonical molecular orbital cont level; comparison between the 193 nm sp spectra of isomers I and II at the P...

The new copper(II) complexes [Cu4(pa)4(Bae)4]·H2O (1) and [Cu4(eba)4(Buae)4]·H2O (2) (Hpa = propionic acid, HBae 2-benzylaminoethanol, Heba 2-ethylbutyric acid HBuae 2-butylaminoethanol) were synthesizsed by the interaction of a copper salt with methanol solution respective ligands. single-crystal X-ray diffraction analysis reveals that both compounds have {Cu4(μ3-O)4} cubane-like core. Both sh...

We here suggest and test a new method to obtain stable energies in proteins for charge-neutral reactions by running large quantum mechanical (QM) calculations on structures obtained by combined QM and molecular mechanics (QM/MM) geometry optimization on several snapshots from molecular dynamics simulations. As a test case, we use a proton transfer between a metal-bound cysteine residue and a se...

The conformational behaviors of 2,3-bis(methylthio)-1,4-dioxane (1), 2,3-bis(methylthio)-1,4-dithiane (2) and 2,3-bis(methylthio)-1,4-diselenane (3) have been analyzed by means ofhybrid-density functional theory (B3LYP/Def2-TZVPP) based method and NBO interpretation.B3LYP/Def2-TZVPP results showed that the axial conformations of compounds 1-3 are morestable than their equatorial conformations. ...